The invention arises as a result of a need for a more reliable and efficient gate valve to control the flow of chemicals including corrosives without leakage and without constant maintenance to free the binding of parts as has been necessitated by prior art valve structures.
In achieving the objectives of the invention, a gate valve has been provided which employs a stainless steel knife edge gate and coacting stainless steel seat, together with means to assure true parallelism and face-to-face contact between the gate and its annular seat. Additionally, the valve employs a bonnet above the casing integrally secured thereto and having opposing parallel guide channels for the gate which further assure its freedom of moving without binding. The channels are provided with clean out means. The valve actuator stem passes through a packing gland above the bonnet cap or top plate and therefore the gate element does not engage or pass through a packing and is sliding contact during its operation with metal faces only. Leakage and binding of moving parts is substantially eliminated in the invention.
Other features and advantages of the valve will become apparent during the course of the following description.